Evolution 707

Home Theater Review

”The Krell Evolution 707 simply is the best AV preamp I have ever heard to date in my home, at any trade show or anywhere else, for that matter.”Read More…

The Evolution 707 aesthetic extends Krell industrial design and takes surround preamplifier/processor construction to an unprecedented level. Housed in the same chassis as the Krell Evolution 402 stereo power amplifier, the Evolution 707 stands nearly 10″ tall and weighs in at over 50lbs. The custom machined aluminum chassis includes diamond cut detailing that not only looks incredible but also fronts the resonance free environment that contains the sensitive electronics within its core. The Evolution 707 includes our finest audio and video engineering plus the latest in connectivity technology, HDMI™ 1.3, and the Krell Automatic Room Equalization System (ARES) to insure the ultimate home theater experience. The audio signal path is a direct descendant of our flagship Evolution 2 stereo preamplifier. The Evolution 707 presents a purity of sound and video resolution previously unavailable in home theater systems.

FEATURES
Based on award-winning preamplifier technology, the Evolution 707 includes twelve output stages with two center channel and four subwoofer outputs, in an 8.4 channel configuration. All channels feature Evolution CAST™ circuitry for the most stunning reproduction of today’s high-resolution movie soundtracks. CAST™, which is short for Current Audio Signal Transmission, is a proprietary method of sending audio signals between components in the current domain. Krell components connected in Evolution CAST™ act together as an electrically unified whole, free from the deleterious effects normally imposed by connecting cables. Balanced outputs and single ended outputs are also included for use with conventional amplifiers. Preamp mode bypasses all digital circuitry and routes the analog input, stereo or 7.1 multi-channel, directly to the 16-bit balanced resistor ladder volume control for the purest signal path possible.

KRELL AUTOMATIC ROOM EQUALIZATION SYSTEM (ARES)

ARES analyzes the speakers’ capability, position, phase and distance relationships to determine ideal crossover points, delay, and volume settings. Listening room surfaces, speaker positioning and construction play a pivotal role in the overall sound quality of a system. ARES measures these effects against the inherent performance of the system’s speakers and corrects for irregular surfaces, problematic speaker locations, and unusual floor plans. A 32 bit dual core DSP running at 1.8 giga operations per second computes equalizer filter coefficients and applies individual curves to each of the 8.4 output channels. A trio of user system memories provides greater flexibility and personalization than other systems on the market. Instead of an averaged result from various listening positions, three individual listening positions may be measured and optimized rather than compromised by an averaging-style system. Alternatively, system memories may be used for different speaker configurations so that one memory can be optimized for two channel listening with full range front speakers, a second memory for movie playback with a crossover and subwoofers engaged, and a third for casual, full range, all-speaker music listening. After each system memory corrects for room anomalies, an optional music or movie curve can be added to the corrected response for an enhanced listening experience. ARES uses on screen prompts to guide the user through the automatic setup and equalization process. The ARES operational range can also be limited to low frequency correction where a majority of sonic irregularities occur. Settings for operation below 63 Hz, 80 Hz, 125 Hz, and 250Hz provide correction in the most troublesome low frequency range while leaving, unaltered, the upper frequency range that helps define a individual speaker’s sonic characteristics.

CONNECTIONS AND OPERATING MODES

Via the four HDMI™ 1.3 compliant inputs, the Evolution 707 is the first high performance surround preamp/processor to decode Dolby TrueHD and DTS HD Master Audio lossless surround formats. Additionally, two Cirrus CS497004 DSPs, running in 64-bit dual precision mode, decode Dolby Digital Surround EX, Dolby Digital 5.1, DTS 6.1 ES, DTS 5.1, DTS NEO:6, Dolby Pro Logic II modes as well as nine proprietary Krell Music Surround modes. The video circuitry takes full advantage of the new Deep Color HDMI™ 1.3 specifications. Maximum color depth has been increased from 24 bits to 48 bits and bandwidth from 165MHz to 340 MHz. Full video transcoding permits any composite, S-Video, or component signal to be routed to the component and HDMI™ outputs and includes upconversion to a maximum of 1080p resolution. Furthermore, the Evolution 707 is a true ”one connection solution” with on-screen display, configuration menus, and status messages available from all active video outputs. HDMI™ 1.3 is at the cutting edge of today’s technology and Krell is the first company to offer a complete solution for reference quality home theaters. The Evolution 707 combines unmatched audio and video performance with all of the convenience features today’s customers demand.